ABSTRACT
Convergence insufficiency (CI) is a binocular anomaly associated with difficulty of the two eyes to converge during near vision. This study investigated the performance of binocular vision in subjects with CI. The performance of binocular vision that comprised of distant binocular visual acuity (VA), near binocular VA and stereoacuity of subjects with CI were compared with normals. Thirty subjects with CI of mean age 17.33 ±5.49 year-old and 30 normal subjects of mean age 18.77 ± 6.08 year-old with visual acuity of VA 6/6 or better, spherical refractive error of no more than ± 4.00 DS, astigmatism no more than 2.00 DC, non-strabismic and never had vision therapy, with good general and ocular health were recruited for the study. The monocular VA of the right eye, monocular VA of the left eye, binocular VA and stereoacuity of the two groups of subjects were measured and the data were compared. Results of the study showed significant differences in the distance binocular VA (t = 2.31, p < 0.05), near binocular VA (t = 0.89, p < 0.05) and stereoacuity (Z = -2.81, p < 0.01) between CI and normal subjects. The study concludes that subjects with CI experienced reduced performances distance binocular VA, near binocular VA and stereoacuity compared with normal subjects.